It is doubtful that they know it is an 8 yr old child. These random calls are not going to stop any time soon. Perhaps it would be better if you took possession of the phone for a while.
I will call the carrier to have it blocked. What's strange is the child just got the phone for emergency so the child needs it. Do you get a call from this number also?
The carrier is saying contact the police first then they will check out the number and block it. I text the number and told them its a child's phone and they have increased their activity bothering my child all day long. Sometimes you have to do what you don't want to do when u are backed in a corner. I pray god has mercy on their souls. Mary other of god